Automation in Display Testing - A Breakthrough Approach 2013-01-0061
Display devices play a vital role as the man-machine interface in most embedded domains including the automotive industry. Display systems provide information regarding the health of various safety critical subsystems and the general status of the machine. Accuracy and precision of the information displayed is a key factor in proper machine operation. Hence display systems need to be tested meticulously before they are delivered to the customer.
The present generation display ECM's (Electronic Control Module) function is not restricted to displaying parameters like fuel level or speed; it also acts as the virtual master of the vehicle. Most display ECMs in off-highway vehicles present at least half a dozen screens to the operator, who selects the one he wants to view based on the need. Hence testing the display ECM becomes as complex as its design.
The testing process covers various aspects like data link communication and conformance with protocol, button behavior and response, accurate displacement of gauges, the timely response of indicators and quick navigation between screens, sanity checks, flashing and compatibility checks.
Most of the display ECM testing is done manually due to the fact that someone needs to physically press the buttons and view the contents on the screen. The tester also needs to verify the behavior of lights on the indicators and the displacement of gauges. Also certain parameters are available only on a particular screen and the tester needs to navigate to that screen and check them. He may also need to manually switch on and off the display or switch off the display without switching off the power etc. Testing generally requires a person to be present to select and program various flash files and run the tests on all the flash files.
Manual testing is not free from human errors, which can lead to safety concerns for both the machine and the operator. There are different methods available to solve this issue, like model-based automated testing and HIL (Hardware-in-loop) testing but they come with their own price tags and usually need dedicated and unique hardware setups to be implemented. These options will add to the product's cost and also complicate testing.
DTA - New Automation Technique
In this paper, we will discuss a breakthrough approach - DTA (Display Test Automation) - which does not require any specific additional hardware or software. In fact, using the concept of DTA, we can develop our own custom software to suit specific purposes. In this paper, we will discuss how this method can reduce time and effort in the software life cycle and improve price-performance ratio. DTA aims to fully automate testing and to solve all the problems and limitations involved in display testing. Once testing of the display ECM is automated, we can extend the idea to all other ECMs and also perform integrated automated testing of the entire machine.